The invention described herein pertains generally to synergistic blends of certain phosphites and lactones having a base structure of 3-phenylbenzofuran-2-one or blends of phosphites, hindered phenol antioxidants, and lactones having a base structure of 3-phenylbenzofuran-2-one.
Various prior art references teach the incorporation of additives into organic polymeric materials. U.S. Pat. Nos. 4,325,863 and 4,325,863 disclose a process for stabilizing organic polymers by incorporating a benzofuran(2)one or indolin(2)one. U.S. Pat. No. 5,175,312 discloses novel compounds of 3-phenylbenzofuran-2-ones while U.S. Pat. No. 5,516,920 discloses novel compounds of 3-arylbenzofuranones and U.S. Pat. No. 5,607,624 discloses methods for their preparation.
The references however, do not disclose the use of synergistic blends of lactones and phosphites with other polymer stabilizers such as UV absorbers and light stabilizers, metal deactivators, peroxide scavengers, basic co-stabilizers, nucleating agents, fillers and reinforcing agents, aminoxy propanoate derivatives, plasticizers, lubricants, emulsifiers, pigments and dyes, optical brightners, flame-proofing agents, antistatic agents, blowing agents, cross-linking agents, antiblocking agents, slip agents, processing aids, and thiosynergists.
What is illustrated in this invention is that various blends of phosphites and 3-phenyl-3H-benzofuran-2-one lactones and/or blends of phosphites, hindered phenol antioxidants, and 3-phenyl-3H-benzofuran-2-one lactones are useful stabilizers for polymers such as polyolefins, polycarbonates, polyesters, etc.